An FPGA controller for deterministic guaranteed-rate optical packet switching

An FPGA controller which can establish low-latency deterministic `Guaranteed-Rate' (GR) transport connections for cloud services is explored. An SDN control-plane can create deterministic GR connections in a forwarding-plane of electrical or optical packet switches, where end-to-end delays are reduced to the fiber latency. A testbed for the proposed deterministic GR technology is presented. A forwarding-plane consisting of 8 controllers and minimum-complexity packet-switches are synthesized on an Altera Cyclone IV FPGA. An SDN control plane routes 128 traffic flows through the forwarding plane, which saturate the packet-switches. Several deterministic schedules are precomputed and loaded into the controller lookup tables, which control each packet-switch for each time-slot in a scheduling frame. The FPGA testbed is clocked at 52 MHz, allowing millions of packet transfers per second, and statistics are recorded. The testbed confirms the establishment of deterministic GR transport connections configured on a programmable underlay network, where the end-to-end delays are effectively reduced to the fiber latency. An inexpensive FPGA controller can add deterministic GR services to IP routers, MPLS, Ethernet, InfiniBand and Fibre channel switches, and layer-2 electrical or optical packet-switches, spanning 100s of nodes over distances of 1000s of miles. By using existing Silicon-Photonics technology, an SDN control-plane can manage deterministic GR connections in a programmable underlay network of integrated single-chip Optoelectronic Packet Switches, with aggregate capacities in the 100s of Terabits/sec.